Apparatus for forming materials



Jan. 23, 1945. J L

' APPARATUS FOR FORMING MATERIALS Filed July 23 1943 Ill-III 11 1 III IJIIIJJIIIJIIIIIIII-- Illllllllll I INVENTOR.

Patented Jan. 23, 1945 APPARATUS FOR FORMING MATERIALS Charles J. Hull, Kenmore, N. Y., assignor to The Rudolph Wurlitzer Company, Chicago, 111., a

corporation Application July 23,1943, Serial No. 495,844

Claims. (01. 18-19) This invention relates to an apparatus for molding sheet plastics, paper, wood, cloth and the like, and particularly that type of material which may be molded'and formed with the application of in association with a flexible sheet, such as rub-.

her, for compresing the material therebetween under equalized high fluid pressiu'e, as more specifically set forth and described in an application of Edward C. Sloan heretofore filed March 22,

1943, Serial No. 480,049, entitled "Method and apparatus for forming materials."

The apparatus comprising this invention includes an arrangement for preventing deterioration of the rubber or rubber composition forming the flexible sheet as a result of the direct application of steam and heat. It is, therefore, the purpose of this invention to protect the rubber or similar composition of the flexible sheet by avoiding the direct application of steam or a heated fluid in building up the fluid pressure thereon. This is accomplished by filling the pressure chamber embodying said sheet with a fluid, such as water or oil, and Ma temperature such as will have no deleterious effect thereon, and whereby said fluid in turn is placed under a pressure to be transmitted thereby to the sheet. In utilizing this invention the heat transfer to and from the material being formed is accomplished through the medium of the metal forming sheet by reason of its high conductivity.

The full nature of .the invention will be understood from the accompanying drawing and the following description and claims:

Fig. l is an illustrative sectional view showing the material being compressed between the sheets within a pressure vessel. Fig. 2 is an enlarged section through a portion of the vessel showing the sheets secured to the respective sections thereof.

In the drawing there is illustrated a pressure vessel l0 having a lower section supported by legs I I and an upper section removably clamped on the lower section by clamps l2. Removably mounted and sealed within the upper section of the vessel there is a rigid forming sheet which consists of a sheet metal die I3. This forming sheet is given any desired shape to which the I material is to be formed. It is only of sufllcient terial. Its lightness and thinness has the advantage of permitting rapid heat transmission to the material formed thereby, as well as the advantage of conveniently and economically forming to various shapes. Thus, said forming sheet in conjunction with the upper section of said vessel encloses a pressure chamber ll.

Removably mounted, but sealed to the lower section to thereby form a pressure chamber l5, there is a flexible conforming sheet it which may be of rubber or rubber composition. This sheet is preferably molded substantially in conformity with the metal forming sheet l3.

The material II to be formed is placed between said sheets and the sections of the vessel are clamped together for the forming operation. High pressure is then applied to compress the material between said sheets and cause it to take the form and set according to the shape of the forming member III by the application of equalizing fluid pressure in the pressure chambers l4, l5. Sinceor deformed as a result of extremely high pressure being applied to the material between the sheets, the flexible conforming sheet being adapted to take the form of the forming sheet and iron. out,

the material into the desired form. At the same time the high pressure will compress the material thus formed to give it high density and set it to form.

The metal forming sheet I3 is secured to arin 18 adapted to be mounted within the upper section of the vessel and removably secured therein in sealed relation with a supporting ring l9 se-I cured to the inner wall thereof. The flexible conforming sheet I6 is secured to a". ring 20 adapted to be seated within said vessel on a ring 2| secured to the inner wall thereof. Thus, each of said sheets may be conveniently removed or replaced within their respective sections and sealed therein to provide the fluid tight pressure chambers l4 and I5.

The pressure chamber I5 is filled with a suitable liquid, such as water or glycerin, from a liquid storage tank 21 having a connection with said chamber I! through an inlet pipe 21. A valve controlled vent 24 is also provided for communication with the upper part of said chamber through a flexible tubing 25 so arranged as to be floated or suspended with its intake in the upper part of the chamber for venting entrapped air. The liquid storage tank 22 contains suflicient liquid to more than flll the chamber while still retaining a high level of the liquid therein.- The top of said storage chamber is connected with a stream and water supply line 28 to which the upper pressure chamber i4 is connectedvby a flexible hose 21. Similarly, the upper chamber may be exhausted of the fluid under pressure through a flexible hose 28 connected with a vent 28 and drain III. The lower portion or the chamber I is also connected with the drain it through a pipe 3|.

By reason .of the flexible hose connections with the upper section of said vessel, it may be readily removed from the' lower section to permit placement of the material therebetween and removable therefrom after i'orming. In forming the material placed between the two sheets, and with the lower pressure chamber i5 substantially but not entirely fllled with liquid from the storage tank 22, steam may be applied to the storage tank and the upper pressure chamber ll. The steam pressure so applied may be raised to any desired amount, such pressure venting any air in the chamber l5 and forcing the conformin flexible sheet and the material engaged thereby against the forming sheet. The equalized pressure on the forming sheet will act to maintainv its shape and prevent collapse while'the steam introduced transmitsth required heat to the material therethrou'gh. However, by reason of introducing the liquid storage tank 22 between the steam pipe and the chamber II, such steam and heat will not be directly applied to the flexible rubber sheet. Thus, it will be protected from the effects of the steam and heat by the interposed liquid in the chamber on the one side and the insulating characteristics of the material being formed on the other side.

The invention claimed is:

1., Apparatus for forming material involving the application of pressure and heat exchange,

including a forming die comprising a thin preformed rigid forming sheet, a complementary rubber conforming sheet, said sheets being adapted to embrace the material, to be. compressed to the form of said forming sheet, a liquid returning receptacle associated with said conforming sheet, a, liquid containing storage tank in communication with said receptacle, and means for applying equalized fluid pressure to said forming sheet and the liquid in said tank.

2. Apparatus for forming material involving including'a formin die comprising'a thin preassure formed rigid forming sheet, said sheet forming a closure portion of a" pressure chamber, a rubber conforming sheet adapted with said forming sheet to compress and form .said material therebetween, a pressure chamber adapted to contain a liquid and associated with said conforming sheet, a liquid storage tank communicating with said last-mentioned chamber, and means for applying equalized fluid pressure to said flrst-mem tioned chamber and tank.

3. Apparatus for forming material involving the application of pressure and heat exchange, including a vessel of opposed separable sections, a forming die comprising a thin preformed rigid forming sheet sealed within one of said sections to enclose a pressure chamber, arubber conforming sheet sealed within the opposed section to v enclose an equalizing pressure chamber adapted to contain a liquid unharmful to the rubber of said conforming sheet, a storage tank for said liquid in communication with said lastmentioned chamber, and a steam pressure line connected with said tank and first-mentioned pressure chamber for transmitting heat to said forming sheet and equalized fluid pressure to said chambers.

4. Apparatus for forming material involving the application of pressure and heat exchange, including a vessel of opposed separable sections, a sheet metal forming die, means for removably mounting said forming die in one of said sections to enclose a pressure chamber, a rubber conforming sheet, means for removably mounting said rubber sheet in the opposed section and sealing it therein to enclose an equalizing pressure chamber, means for securing said separable sections of the vessel together with the material to be formed extending between said die and conforming sheet, said last-mentioned pressure chamber being adapted to contain a liquid unharmiul to the rubber oi said conforming sheet, a storage tank for said liquid in communication with said last-mentioned chamber, and a steam pressure the application of pressure and heat exchange,

line connected with said tank and first-mentioned pressure chamber for transmitting heat to said metal die and equalizing the fluid pressure withinsaid chambers.

5. Apparatus for forming material involving the application of pressure and heat exchange, including a forming die comprising a thin preformed rigid iorming sheet, a complementary rubber conforming sheet, said sheets being adapted to embrace the-material to be compressed to the form of said forming sheet, a liquid retaining receptacle associated with said conforming sheet with the liquid in direct contact therewith, and means for applying equalized fluid pressure to said forming sheet and the liquid retained in said receptacle, whereby said pressure will be transmitted through the medium oi said liquid to the conforming sheet.

', CHAR.LESJ.HUIL. 

